I am trying to create a check in form and use the serial number of a piece of equipment  we have received as a way of automatically adding customer information to the form. We work with the same customers and equipment over and over and thought using the serial number would be the quickest way possible to identify the customer rather than typing it in every time. I assume it will be a lookup field, maybe a sub form? I have a customer list that has the serial number on it. Any help would be appreciated!